420DB – Bridge A/C and Heat Installation

I have one installed from sea ray. It works great but runs very hard on sunny days. 1,600. Crusair unit. It blows 56 degree air with water temp coming in unit at 89.1 degrees. I really think a bigger unit with all the glass is needed. If I can help with more info, would be glad to. As info, I just back flushed all my units and water flow increased by 4 gals and air cooling by 2 degrees. Unit was installed 2008.
 
Labbur said:
I have one installed from sea ray. It works great but runs very hard on sunny days. 1,600. Crusair unit. It blows 56 degree air with water temp coming in unit at 89.1 degrees. I really think a bigger unit with all the glass is needed. If I can help with more info, would be glad to. As info, I just back flushed all my units and water flow increased by 4 gals and air cooling by 2 degrees. Unit was installed 2008.
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Thank you for your input. I'm pretty much done with my "shopping list" and in the process of placing the order. I'm sure that as I'll begin the installation I'll have tons of questions.
 
Hey Guys,

I need some tips regarding the pump relay. I spoke with Ocean Breeze and they told me that it's possible that SR installed a pump relay that can handle 3 units. I kind of doubt it, but Joe (from DB) told me just open the relay cover and see if there's an extra input. As you know my boat has 2 units and (as I understand) a single relay that controls both units. I've never opened one up. I imagine that there should be at least two input lines from the units (and hopefully 3rd one unused) and one output line to the pump to trigger it.

Does anyone know if our relays can support 3 units? Are there any limitations in existing relay I should be concerned about?
 
beachcombersc said:
More than likely there will be an empty spot so you can purchase another trigger...
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Oh, thanks.....that would be great. What kind of trigger am I looking for?
 
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Great! Thanks for the tips. I'm sure that once I'll open the box I'll have much better understanding what I'm up against. Now i just hope that there's an empty slot for one more unit.
 
The most common one used has three spots, they go up from there...

You will most likely have to buy the trigger still.
 
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Alex, somewhere in this thread I thought you were considering using 2 pumps tied to your single seacock (with either 1 or parallel sea strainers). This approach seemed fit many your design criteria and would give you a potential back-up pump if you lost your interior A/C pump. Do you mind sharing why you abandoned this approach? Thanks, Art
 
Art said:
Alex, somewhere in this thread I thought you were considering using 2 pumps tied to your single seacock (with either 1 or parallel sea strainers). This approach seemed fit many your design criteria and would give you a potential back-up pump if you lost your interior A/C pump. Do you mind sharing why you abandoned this approach? Thanks, Art
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Art,

Yes using single seacock and strainer to feed two separate pumps was one of the options. However, after speaking with pump manufacturer, Sea Ray and having feedback from others I've concluded to stick with the simplest method as the new larger pump will be more than adequate for the job. The pump I'm installing is even more powerful than the one SR uses for this installation. It's rated for 41' head @30GPM and can support up to 72000BTU (if my memory serves me right), combination of my 3 units will be only 54000BTU. My existing pump will be in the spare parts box as a backup. BTW, another reason is also that, as far as I recall, I would have to get pretty much the same pump even for single bridge A/C unit. If not 100% the same, but close to it. So, if I have to get almost the same pump I figured that it's not worth messing with the new strainer. The problem is that I'd have to change mine and get the one with multiple outputs (mine is like most of us have, single input single output). Based on the feedback from most of the sources it just didn't make sense to me.

If you recall what I've posted earlier, SR does this optional install using simple approach: single seacock/strainer, single but larger pump and only one or two vents. My basic approach is kind of similar but major differences are:
1. I'm using even bigger pump.
2. I'm using bigger unit.
3. I'll be installing at least 4 but possibly up to 6 vents to get the air moving much better.
4. I'm looking in to something I just learned, a more intelligent programmable relay. Based on preliminary and limited knowledge this is a relay that will be able to monitor "what's running" and prevent triggering the third unit. This is so far my "backup plan" in case if someone messes up the manual power management between 3 units. I'll be posting questions on it and if it's not too expensive I may go for it.
 
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Alex, Thanks for the explanation. Good luck with your project, and more importantly, many happy hours of boating with your family.

Art
 
Hey guys, is anyone familiar with PLCs (Programmable Logical Controllers)? I'm under the impression that this is a solution to the power management issue between 3 units. I found few but looks like the output APMs are too low.

http://www.grainger.com/Grainger/programmable-controllers/programmable-logic-controllers-plc/electrical/ecatalog/N-gsa?Ndr=basedimid10071&Ns=List+Price|0&sst=subset&sort=DD

I think I might have to open dedicated thread on this subject as it's another can of worms. But, if anyone who's watching this thread has some suggestions, I'd appreciated.
 
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I don't think these are appropriate for your application. I think these are for time dependent events, like turning lights or A/C at programmable times or intervals.

Art
 
Thanks Art, I'm keeping my fingers crossed that there's something out there. OB folks gave me a hope that there are number of products on the market that can monitor the load and I just have to find the right one and within reasonable budget. I'm waiting for Grainger technical expert to call me back regarding my inquiry.
 
Alex F said:
Hey guys, is anyone familiar with PLCs (Programmable Logical Controllers)? I'm under the impression that this is a solution to the power management issue between 3 units. I found few but looks like the output APMs are too low.

http://www.grainger.com/Grainger/programmable-controllers/programmable-logic-controllers-plc/electrical/ecatalog/N-gsa?Ndr=basedimid10071&Ns=List+Price|0&sst=subset&sort=DD

I think I might have to open dedicated thread on this subject as it's another can of worms. But, if anyone who's watching this thread has some suggestions, I'd appreciated.
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What exactly is the issue you're concerned with again? The power management between the 3 AC units?

Doug
 
douglee25 said:
What exactly is the issue you're concerned with again? The power management between the 3 AC units?

Doug
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Yes, Doug that's it. The more I think about it the more I'm convincing myself that I have to apply "my rule #1", which is always have a backup. In this case manually controlled power management leaves a room for human error. I'm thinking of scenario when I'm not on board (let's say I went out fishing on a dinghy) and my kids decide to have breakfast on the bridge, but it has to be cooled off first. I can guaranty that if I tell them 1000 times to turn off FWD A/C it'll be just one of those "ooops, sorry dad, we forgot..." things. So, I need to cover this "point of failure".

My original idea was to have some sort of a switch, but then when I've heard of PLCs I thought it would be cool if I can have a small controller to keep an eye on it for me. Oh well, I just spoke with Grainger tech and he told me that sure it can be done, but the complete product will cost me close to $2K. So, he suggested to go back to my simple and manual solution of using a toggle switch, like this one: http://www.grainger.com/Grainger/ww...=2vln6|2vln6&N=0&GlobalSearch=true&sst=subset

Obviously the fancy-shmency PLC idea goes out of the window and so far looks like the toggle switch is the way to go.

For those who's not very familiar with what it'll do, here's a quick explanation. I'll label the units for argument sake:
#1=salon
#2=FWD stateroom
#3=bridge

My goal is to allow for only any given TWO units to have power supplied to them. This way only TWO units can run at the same time. Let's say the switch has positions 1 & 2. In position 1 it'll supply power to units #1 and #2 (salon and FWD), this means that unit #3 (bridge A/C) will be dead with no power. When I want to run unit #3 I'll flip the switch to position 2 where it'll feed another set of units (#1 and #3) disconnecting the juice from unit #2 (FWD).

I think this is very simple and effective solution. Now I can sign and send my waver to SR......oh crap, I'm out of warranty.
 
For home stand-by generators Onan sells load controllers that do essentially what you want. Have you talked with them?
 
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